Control of Grid Frequency under Unscheduled Load Variations: A Two Layer Energy Management Controller in Urban Green Buildings

Abstract

Demand side response (DR) became a major tool to the utility companies with the integration of many smaller grids. DR helps to manage the fluctuations in the grid which leads to cost optimization. However, in undeveloped electricity markets the operation of DR is very limited. In such cases, proper energy management controller helps to operate the interconnected microgrids with proper power sharing and minimum frequency deviations. By keeping this point in view this paper proposes, A Two Layer Energy Management Controller (TLEMC) to manage the generations and loads in the system formed by interconnecting four microgrids and is referred as Minigrid’. In the minigrid system each microgrid (MG) is associated with locally available renewable energy sources (RES) such as photovoltaic (PV), wind (WP), fuel cell (FC), storage systems and local building loads. The proposed controller effectively incorporates interoperability concept in the system considered for study, i.e., the power is shared in between the interconnected microgrids during excess/deficit power conditions. The robustness of the proposed controller is verified by comparing frequency deviations and the exchange of power in the interconnected system under unscheduled loading conditions and also the performance of the controller is tested in the presence of DR. The system configuration and proposed controller considered in this paper are developed in MATLAB/Simulink environment, and from the THD analysis effectiveness of the proposed controller is verified